This revised application is in response to PAR-06-114, "Research on Pathways Linking Environments, Behaviors and HIV/AIDS" and requests five years of support examine the relationship of HIV vulnerability to changes in economic environment and food security in rural Malawi. We have formed a multidisciplinary research team and partnered with CARE Malawi/USA to conduct three related studies: 1. We will conduct a quasi-experimental non-equivalent control group longitudinal study of the mechanisms, processes, and magnitude of impact of a large multi-level development and food security intervention (Improving Livelihoods through Increasing Food Security, or I-LIFE), as implemented by CARE Malawi, on HIV vulnerability (i.e., HIV risk behaviors, malnutrition, HIV infections, deaths due to HIV) and economic outcomes (i.e., food security, income, household assets). We will recruit participants from three types of areas of rural central Malawi: areas selected to receive the I-LIFE intervention from CARE, areas that will not receive I-LIFE but are participating in other CARE programming, and areas not receiving CARE programming during the life of the study. We will assess HIV-related, food security, and economic outcomes at both at the individual and community levels. In each of the CARE program areas, we will recruit 600 program participants and interview them at baseline and three yearly follow-ups to contrast I-LIFE participants directly with other CARE program recipients. We will examine broader changes at the community level, also hypothesized to result from the I-LIFE intervention, by conducting surveys with 1000 randomly-selected households in each of the 3 types of study areas at baseline and at a 36 month follow up. 2. We will conduct theory-based statistical analyses of longitudinal data collected in (1) to test pathways between socioeconomic changes, food security, HIV risk behavior, and HIV-related outcomes. 3. We will conduct a thorough qualitative end-of-program evaluation consisting of in-depth qualitative interviews with I-LIFE participants to understand the perceived impact of I-LIFE on their lives and the mechanisms of this impact. PUBLIC HEALTH RELEVANCE: The proposed research is directly relevant to public health by examining the effects of a multi-level intervention on HIV-related outcomes in Malawi, a country in sub-Saharan Africa with a high prevalence of HIV infection. In addition to examining the role of changes in economics and food security to HIV vulnerability, the proposed research will yield important information for determining the impact on HIV of multi-level environmental/structural interventions with the potential for sustainable long-term public health benefits, as well as for refining and improving the specific intervention under study for increased implementation.